Background: Shifting to active modes of transport in the trip to work can achieve substantial co-benefits for health, social equity, and climate change mitigation. Previous integrated modeling of transport scenarios has assumed active transport mode share and has been unable to incorporate acknowledged system feedbacks.Objectives: We compared the effects of policies to increase bicycle commuting in a car-dominated city and explored the role of participatory modeling to support transport planning in the face of complexity.Methods: We used system dynamics modeling (SDM) to compare realistic policies, incorporating feedback effects, nonlinear relationships, and time delays between variables. We developed a system dynamics model of commuter bicycling through interviews and workshops with policy, community, and academic stakeholders. We incorporated best available evidence to simulate five policy scenarios over the next 40 years in Auckland, New Zealand. Injury, physical activity, fuel costs, air pollution, and carbon emissions outcomes were simulated.Results: Using the simulation model, we demonstrated the kinds of policies that would likely be needed to change a historical pattern of decline in cycling into a pattern of growth that would meet policy goals. Our model projections suggest that transforming urban roads over the next 40 years, using best practice physical separation on main roads and bicycle-friendly speed reduction on local streets, would yield benefits 10–25 times greater than costs.Conclusions: To our knowledge, this is the first integrated simulation model of future specific bicycling policies. Our projections provide practical evidence that may be used by health and transport policy makers to optimize the benefits of transport bicycling while minimizing negative consequences in a cost-effective manner. The modeling process enhanced understanding by a range of stakeholders of cycling as a complex system. Participatory SDM can be a helpful method for integrating health and environmental outcomes in transport and urban planning.Citation: Macmillan A, Connor J, Witten K, Kearns R, Rees D, Woodward A. 2014. The societal costs and benefits of commuter bicycling: simulating the effects of specific policies using system dynamics modeling. Environ Health Perspect 122:335–344; http://dx.doi.org/10.1289/ehp.1307250

The energy cultures framework was developed in 2009 to support interdisciplinary investigation into energy behaviour in New Zealand. In this paper, we discuss the framework in light of 5 years of empirical application and conceptual development. The concept of culture is helpful in seeking to better understand energy behaviour because it conveys how behaviours are embedded within the physical and social contexts of everyday life, and how they are both repetitive and heterogeneous. The framework suggests that the energy culture of a given subject (e.g. an individual, a household, a business, a sector) can be studied by examining the interrelationships between their norms, practices and material culture, and how these, in turn, are shaped by external influences. We discuss the key theoretical influences of the framework, and how the core concepts of the framework have evolved as we have applied them in different research situations. We then illustrate how we have applied the framework to a range of topics and sectors, and how it has been used to support interdisciplinary research, in identifying clusters of energy cultures, in examining energy cultures at different scales and in different sectors, and to inform policy development.

Many children globally do not meet government guidelines for daily fruit and vegetable intake, and in New Zealand, adherence to the vegetable intake recommendation is declining. This study aimed to identify systemic barriers to children meeting fruit and vegetable (FV) guidelines and generate sustainable actions within a local community to improve children’s FV intake. A qualitative system dynamics method of community group model building was used. The research team partnered with Healthy Families Waitākere, a Ministry of Health funded prevention initiative, to recruit 17 participants (including students, parents, teachers, community leaders, local retailers and health promoters) from a low-income, ethnically-diverse community in West Auckland, New Zealand. Three group model building workshops were held during which a systems map was created and used to identify actions by considering causal pathways and reinforcing loops in the system. Barriers to children’s FV intake identified by participants were the saturation of fast-food outlets in the community and ubiquitous marketing of these products, the high cost of fresh produce compared to fast food, and parents having little time for food preparation plus declining cooking skills and knowledge. Several actions to improve children’s FV intake by improving the local food environment were identified, which will be co-designed further and tested by a collaborative group involving community leaders. This project highlights the effectiveness of group model building for engaging a local community in systems change to improve child nutrition, and supplies a blueprint for future qualitative system dynamics research.

Group model building (GMB) is a qualitative method aimed at engaging stakeholders to collectively consider the causes of complex problems. Tackling inequities in community nutrition is one such complex problem, as the causes are driven by a variety of interactions between individual factors, social structures, local environments and the global food system. This methods paper describes a GMB process that utilises three system mapping tools in a study with members of a multicultural, low-income community to explore declining fruit and vegetable intake in children. The tools were: (1) graphs over time, which captures the community’s understanding of an issue; (2) cognitive mapping, which enables participants to think systemically about the causes and consequences of the issue; (3) causal loop diagrams, which describe feedback loops that reinforce the issue and identify potential actions. Cognitive mapping, a tool not usually associated with GMB, was added to the research process to support the gradual development of participants’ thinking and develops the skills needed to tackle an issue from a systems perspective. We evaluate the benefits and impact of these three tools, particularly in engaging participants and increasing understanding of systems thinking in order to develop and mobilise action. The tools could be adapted for use in other community-based research projects. Key learnings were the value of genuine partnership with a local organisation for longevity of the project, recruitment of key decisionmakers from the community early in the process, and allowing time to create sustainable change.

WHEN a new process is suggested for use in agriculture or technology it is usually necessary to carry out experiments to estimate the increase in output that would result if the new process replaced that in current use. If the cost of experimentation and the scale of potential application of the new process are known, one method of arriving at an optimum amount of experimentation is to minimize the total risk given by the sum of the cost of the experiment plus the expected loss due to wrong decisions. The main difficulty is that the last quantity depends on the true increase in output due to introducing the new treatment, which can only be estimated from the results of the experiments. The paper discusses the case where an initial experiment is carried out, and it is required to decide whether to accept or reject the new treatment at once or else to carry out further experimentation. In the latter case the optimum amount of further experimentation has also to be decided. A solution is provided by minimizing the risk' after eliminating the unknown parameter by averaging over its fiducial distribution based on the evidence from the initial experiment. Means for applying the resulting decision rule in practice are provided, and its performance under various circumstances is discussed.